Five months to go until HP-day, and the madness has already begun. Amazon announced this morning that in the seven weeks since JK Rowling revealed the publication date of the penultimate Potter, Harry Potter and the Half-Blood Prince, it has already taken a whopping 100,000 pre-orders for the book.

The latest instalment in the history of Hogwarts School of Witchcraft and Wizardry is due to burst onto the bookshelves on July 16. Rowling unveiled the date on her website on December 21, to those readers who were able to prove their fan credentials by solving a series of Harry-related riddles.

If the launch of the fifth book in the series, Harry Potter and the Goblet of Fire, is anything to go by, Amazon's announcement is just the beginning. The online bookseller, which has its own dedicated Harry Potter store, shipped 420,000 pre-ordered copies of the Goblet of Fire in 2003; on the day it appeared in the shops, 1.8m copies were sold.

Bookshop owners around the UK dressed up in full robe-and-wand regalia to hold events and parties for younger readers, while supermarkets and the bigger bookstores battled to see who could offer the biggest discounts. With the frenzy surrounding Harry Potter and the Half-Blood Prince expected to equal, if not excel, that of its predecessor, it's time to hold on to your (pointy) hats.